Sizing of dyed yarn



Patented Aug. 9, 1932 UNITED STATES PATENT OFFICE HERBERT PLA'IT, OFCUMBERLAND, MARYLAND, ASSIGNOR TO CELANESE CORPORA- TION OE AMERICA, A.CORPORATION OF DELAWARE SIZING OF DYED YARN No Drawing.

This invention relates to the sizing of yarn that has been previouslydyed, and relates more particularly to the sizing of yarn containingorganic derivatives of cellulose, which have been dyed with a dye thatis normally insoluble in water.

An object of my invention is to dye yarns of all kinds, but particularlyyarns made of.

or containing organic derivatives of celluw lose such as celluloseacetate, in such a manner that the dyed yarn suii'ers but little changein color after the sizing compound is removed.

The sizing of dyed yarn, and particularly yarn containing organicderivatives of cellulose that have been dyed with certain waterinsoluble dyes that are solubilized by means of a dispersing agent, hasheretofore presented serious dilficulty. If an attempt is made to 2 sizesuch dyed yarn by the ordinarymethods, it is found that the color tendsto bleed both into the sizing bath and also into the bath that is usedfor removing the size after the required textile operation. Moreover,the textile product thus formed is often dull in color and has otherundesirable characteristics.

In accordance with my invention, I treat a yarn containing organicderivatives of celluose, that has been dyed in any desired manner, witha sizing composition containing glue or gelatin that is substantiallyneutral and at a suitable temperature.

The yarn to be treated in accordance with my invention may contain anysuitable or- 3: ganic derivatives of cellulose such as organic esters ofcellulose or cellulose ethers. Examples of organic esters of celluloseare cellulose acetate, cellulose formate, cellulose-propionate andcellulose butyrate. Examples of cel- 40 lulose ethers are ethylcellulose, methyl cellulose and benzyl cellulose.

The yarn may consist wholly of one or more of these organic derivativesof cellulose or it may be a mixed yarn containing fibres of 46 theseorganic derivatives of cellulose and Application filed J uly -13,

fibres of other materials such as cotton, silk or wool. Examples of suchmixed yarns are mixed cellulose acetate and cotton and mixed celluloseacetate and wool.

The yarn to be sized may be dyed by any suitable dye. However, thisinvention is particularly applicable to yarns that have been dyed withWater insoluble dyes which have been solubilized by a dispersing agent.An example of a series of such dyes, are the anthraquinone vat dyes inthe unreduced state dispersed in aqueous suspension by means ofdispersing agents, such as sulpho fatty acids of which sulpho ricinoleicacid is an example. The yarn may be dyed by a single dye or by a mixtureof dyes to obtain the desired color.

The sizing bath contains glue or gelatin and is substantially neutral.It may be slightly alkaline but it is preferable that it should not havean acidic reaction. Generally a sizing bath having a pH value of 7 to7.5 is preferred in my process. The temperature of the sizing bathshould preferably be from 60 to 80 0. I have found that a temperature of70 0. produces the best results.

After the yarn has been sized in the bath it may then be woven orknitted into a fabric or subjected to any other desired textileoperation. The material is then desized by submersion in or by othertreatment with Water at a temperature of 50 to 70 C. but preferably C.The dye bleeds but little and the textile material thus produced isfound to have a color that is substantially as bright as the dyedmaterial before it has been sized.

In order further to illustrate my invention the following specificexample is given but my invention is not limited thereto.

Example A yarn consisting wholly of cellulose acetate is dyed with anysuitable dye, such as 1.4 dimethyldiamino anthraquinone or 2.4 dinitro 4amino diphenylamine dispersed in aqueous suspensions by means of sulphoricinoleic acid, or any other dyes such as getacyl or the so calleddirect or dispersol yes. The dyed yarn is then sized with a sizingcomposition at 70 (3., such composition being made up as follows:

Gelatin 9 pounds 10 Glycerine -3 2 pounds Castor oil a 1.5 pounds Sodiumbenzoate 0.25 ounce Water 260 pounds This bath is caused to have a pHvalue of 7.0 to 7.5 by the addition of 1 lb. ,5 ozs. to 1 lb. 6' ozs. ofsodium carbonate. Because of the pH value of this sizing composition,change of shade of the dyed yarn is prevented, with practically nobleeding of the e. It is to be understood that the foregoing detaileddescription is given merely by Way of illustration and that manyvariations may be made therein without departing from the spirit of thisinvention.

Having described my invention, what I claim and desire to secure byLetters Patent is:

1. Method. of sizing yarn containing organic derivatives of cellulose,which yarn has previously been dyed with a water insoluble dye that isdispersed in an aqueous liquid by means of a 'sulfo-fatty acid,comprising treating the same with a sizing bath containing gelatin whichbath has a vpH value of substantially 7 to 7 .5, at a temperature of 60to 80?.

2. Method of sizing yarn containing cellulose acetate, which yarn haspreviously been dyed with a Water insoluble dye that is dispersed in anaqueous liquid by means of a sulfo-fatty acid, comprising treating thesame with a sizing bath containing gelatin which bath has a pH value ofsubstantially 7 to 7 .5, at a temperature of 60 to 80 C.

3. Method of sizing yarn containing cellulose acetate, which yarn hasbeen previously dyed with an anthraquinone vat dye in the unreducedstate that is dispersed in an aqueous liquid by means of a sulforicinoleic acid comprising treating the same with a sizing bathcontaining a gelatin which bath has a pH value of substantially 7 to7.5, at a temperature of substantially 7 0.

In testimony whereof, I have hereunto subscribed my name.

HERBERT PLATT.

